I sold a "reasonable" Haf last year for ~£5.5k. Mechanically sound but some tin worm in the body panels. As Pete says, £10k would get you a very nice one, but it is just the luck of the draw if and when one comes up in the condition that you are comfortable with.

My "restored" Haf is worth much more than that to me, so I'll hang on to it for a while :)

Question is if you are after a "restored" one, LHD or RHD , civilian or military. Are you prepared to buy from Europe or are you specifically after UK vehicle. There will be premium for a "fully" restored Haflinger as opposed to a "working" vehicle, but I am sure you know that already.

There are more available from Europe than local UK ones, so you might be waiting a while if want a UK one.